Although stories of people who are half-human and half-fish exist in many cultures around the world, there is no existing proof that mermaids actually exist. The widespread popularity of the myth can be attributed to traders and explorers sharing stories when they encounter new cultures.
There is evidence that many of the mermaids in African and American indigenous cultures were originally a different type of water spirit, but took on characteristics of the European mermaid after contact with European sailors.
According to the American Museum of Natural History, it is possible that sightings of manatees. or other marine animals, explain the firsthand accounts of mermaid sightings. Taxidermists also created fake mermaids for display. The most famous example was P.T. Barnum's "Feegee Mermaid," which he created by sewing a deceased monkey and fish together.